why can i not buy music?

i cant change my payment info. this is ridiculous! ive changed my password forgot my login questions(that i cant change) now i cant buy music! i have a gig Sunday i need to buy some songs for. wouldn't let me put my card info in so i bought a card and now it wont let me use it cause it wants pay info...which it wont let me change! fix this or its amazon here i come!!!!!